We build 4B11T engines to a target power level rather than selling you a pile of parts and wishing you luck. Four specs: 650, 850, 1000 and Race.
The question we get asked most is which one to buy. The honest answer is that it depends on three things, and horsepower is only one of them.
Long block or short block?
Before the spec, the format.
- A short block is the bottom end: block, crank, rods, pistons, bearings. You supply the head. Cheaper, and it makes sense if your head is healthy or you already have a built head.
- A long block is the short block plus a cylinder head, assembled. You bolt on your accessories and go.
If your head has been through a head gasket failure, has high miles, or is untouched and you are targeting big power, buy the long block. A built bottom end under a tired head is a false economy - and on this platform the head is where the gasket problems announce themselves.
The three questions that actually decide it
1. What is your real power target?
Not your dream number. The number you will actually tune to and drive. People routinely buy an engine for the power they hope to make in three years and then never get there, having paid for capability they never used.
2. How do you use the car?
This matters more than the peak number. A 600 whp street car that sees full throttle for four seconds at a time is a completely different duty cycle to a 600 whp track car doing twenty-minute sessions, or a drag car doing repeated launches on sticky tyres.
Sustained load and repeated heat cycles are what kill engines. If you run the car hard, buy more engine than your dyno number suggests.
3. What is downstream of it?
An engine that makes more torque than your transmission will hold is a very expensive way to break a transmission. If you have the SST, be realistic about what it will take before you order the 1000 spec.
Roughly how they map
650 Spec
The sensible one, and the right answer for most people. A properly built bottom end for a strong street car that you want to stop worrying about. This is the spec that covers the enormous middle of the Evo X world - people who have outgrown stock internals and are not chasing records.
650 short block | 650 long block
850 Spec
Serious power, and the point at which the block itself has to be addressed rather than just the parts inside it. See sleeved vs unsleeved for why.
850 short block | 850 long block
1000 Spec
Four-figure territory. Everything in the engine is chosen to survive cylinder pressures that would fold a stock block in an afternoon. At this level the car is built around the engine, not the other way round.
1000 short block | 1000 long block
Race Spec
No compromises, because the car has no other job. If you are asking whether you need Race spec, you almost certainly do not - the people who need it already know.
The mistake we watch people make
Buying too much engine and then having no budget left for the things that keep it alive.
A 1000 spec engine behind a stock intercooler, a marginal fuel system and a cheap tune will not make 1000 whp. It will make whatever the weakest link allows, and then it will die of detonation like any other engine, except you will have paid four figures more for the privilege.
The engine is not the build. The engine is one part of the build. Fuel (injectors, a real fuel system), charge cooling (intercooler), oil control (baffled pan, oil cooler) and engine management (MoTeC M150) are not optional extras. They are the difference between the number on the box and the number on the dyno.
If the budget only stretches to a 650 spec plus a proper supporting cast, buy the 650 spec. It will be faster, more reliable and cheaper than a 1000 spec with corners cut around it.
Talk to us before you order
This is exactly the conversation we would rather have on the phone than watch you guess at in a shopping cart. Tell us the car, the fuel, the transmission, the power goal and how you use it. We will tell you which engine you need - including when it is a cheaper one than you were about to buy.